Today you’ll learn about how our genes can predict how many kids we’ll have, how scientists have created a new method of sucking up CO2 from the atmosphere, and how a baby mouse was born from two biologically male mice!
Today you’ll learn about how our genes can predict how many kids we’ll have, how scientists have created a new method of sucking up CO2 from the atmosphere, and how a baby mouse was born from two biologically male mice!
Genetic Fertility
CO2 Suck Up
2 Dad Mice
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Find episode transcripts here:https://curiosity-daily-4e53644e.simplecast.com/episodes/genetic-fertility-co2-suck-up-2-dad-mice
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NATE: Hi! You’re about to get smarter in just a few minutes with Curiosity Daily from Discovery. Time flies when you’re learnin’ super cool stuff. I’m Nate.
CALLI: And I’m Calli. If you’re dropping in for the first time, welcome to Curiosity, where we aim to blow your mind by helping you to grow your mind. If you’re a loyal listener, welcome back!
NATE: Today you’ll learn about how our genes can predict how many kids we’ll have, how scientists have created a new method of sucking up CO2 from the atmosphere, and how a baby mouse was born from two biologically male mice!
CALLI: Without further ado, let’s satisfy some curiosity!
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NATE: It turns out that we might be able to tell how many babies somebody could have just by studying their genes.
CALLI: Okay, so I don't have any babies. I wear skinny jeans usually or sometimes like bootcut. Are you telling me that these are determined genetics? Not genetics, not blue jeans. Okay. Please carry on.
NATE: Well, this is actually just the tip of the iceberg. The study, which involved researchers from Cambridge, Oxford and the University of Pennsylvania, found 43 places in our genomic loci, which is basically like an address for our genes that are associated with either the number of babies born or with childlessness. Another example for a genomic loci would be for, say, My Brown Eyes is the location of that trait in my genome. And loci is just the plural for locus.
CALLI: So researchers found the addresses in our genes for how many babies we could have.
NATE: That is right. And it just so happens that they are the same addresses for many other traits that determine aspects of our reproductive biology, like the timing of puberty, the age at first birth, the age at menopause, even the likelihood that someone suffers from endometriosis.
CALLI: Oh, okay. So what does all this mean?
NATE: A lot. First, it allows researchers to find associations between genes and outcomes. For example, some variants were associated with more babies, but also with a shorter reproductive lifespan, which means in that loci, there's some kind of biological tradeoff between having a ton of babies and having babies for a long time.
CALLI: So have a bunch of kids and retire young or have fewer kids over a longer period.
NATE: Something like that, Yeah. But understanding these genetic associations can help scientists study fertility, which could lead to new effective treatments for infertility. But there is a very big, very nerdy twist to this story.
CALLI: Nerdier than explaining the plural for locus.
NATE: I'm afraid so. It's not just what they found, it's how they found it. This study was massive. They looked at data from 785,604 individuals for what is reportedly the biggest study to date of its kind. And with such a big study, they found one of the holy grails of many different scientific disciplines: evidence of ongoing natural selection.
CALLI: Okay, that is really nerdy. What what does this mean?
NATE: Well, let's talk about natural selection for a second. In its most basic form, natural selection means that traits that help the individual tend to end up in the next generation. And traits that hurt the individual, well, they eventually disappear. But scientists have only ever been able to examine natural selection across tens of thousands of years or more. Until now, with such a massive dataset, almost 800,000 individuals, researchers can actually see selection that has happened in the recent past, or even that is still going on. And that is a first.
CALLI: Did this study actually find ongoing natural selection?
NATE: They think so.
CALLI: So what are the implications of that?
NATE: Well, that's sort of the million dollar question. They aren't sure exactly what the reason is for the natural selection. So much data can be really, really hard to interpret. But researchers think that this can open up a huge world of insight into the way we've evolved and are still evolving and can show us how our environment actually shapes our own genetic makeup. For example, we could see how our genotypes are reacting to certain chemical pollutants.
CALLI: Okay, very, very cool.
NATE: The findings are definitely exciting, especially for anyone interested in reproductive health and nerdy, breaking, natural selection based news.
CALLI: I'm always here for nerdy news
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CALLI: Recommendations from the Intergovernmental Panel on Climate Change. The IPCC say the world should be at net zero emissions of carbon dioxide by 2050. But guess what?
NATE: It will not be.
CALLI: That is sort of an understatement. By some estimates, we are still producing over 36 gigatons of CO2 every year, and that's not a made up number. It gigaton, in case you're wondering, is a billion tons. To put that into perspective, if all the CO2 was in ocean, it would almost totally cover Texas, New Mexico, Arizona, California, Nevada, Utah and a bit of Colorado at a depth of 27 feet.
NATE: Oh, my goodness. Every single year.
CALLI: Every single year. But there's a new hope on the horizon. Researchers have developed a new way to capture carbon dioxide that they say is able to suck up to three times as. Much as current carbon capture methods, and that is a big deal.
NATE: We've been hearing about carbon capture for a long time, but it hasn't really made much of an impact yet. Will this change that?
CALLI: It's a start, to be sure. But before we get into the new tech, let's talk a little bit about carbon dioxide.
NATE: I know a little bit about this one. It's a greenhouse gas, that is, it traps heat in the atmosphere like the walls and ceiling of a greenhouse. And that heat wreaks havoc on our climate systems.
CALLI: Yes, exactly. Nail it on the head and seeing how we put so much of it into the air every year, you do think that we must be just swimming in it. But that's not the case. Carbon dioxide is an incredibly potent greenhouse gas, so it doesn't take a lot to have huge impacts. In fact, as of right now, if you had like a little balloon full of 1 million particles of atmosphere, only around 400 of those particles would be CO2. Imagine going into a city where a million people lived and trying to find 400 people, you know, who were just randomly hanging out.
NATE: It's like the ultimate Where's Waldo, except those 400 waldos are melting the ice caps.
CALLI: This is the problem with existing carbon capture methods. It turns out it's really hard to find all those Waldos and just yank them out of the air. In fact, with the kind of energy needed, you risk putting more CO2 into the air than you can capture, which just doesn't make any sense. And when you can make a system that is effective, it's incredibly expensive. There probably isn't enough money in the universe to build enough of them to capture all the carbon dioxide we need to capture.
NATE: Okay. So this is why it's still in the realm of just hypothetical.
CALLI: Exactly. And other capture methods like planting trees are theoretically cost effective unless you take into account the incredible amount of land needed to do the job.
NATE: Right. So what about this new technology?
CALLI: So lead author Professor Arup SenGupta from Lehigh University looked at the problem of carbon capture from a different angle. He found an existing technology that was designed for use in water and repurposed it to suck up CO2 from the air.
NATE: How does that work?
CALLI: That's one of the cool parts of the story. It uses common chemicals and resins and is shown to pole as much as three times the carbon dioxide out of the air as current methods. An example of a current method is a post combustion carbon capture, which uses a chemical solvent that captures CO2 from power plants. This method from Professor SenGupta is cheaper and more effective, and as a bonus, it turns this carbon into bicarbonate of soda that can be stored in the sea in former oil wells. And before you say anything, the scientists assure that it is a very safe way to store that Bicarbonate of soda.
NATE: Bicarbonate of soda? You mean like baking soda.
CALLI: Basically.
NATE: Okay. This all sounds a little too good to be true. Like, are all of our climate problems just solved now?
CALLI: No, not quite. They still need to scale this up. And there is a vastly better way to get carbon out of the atmosphere. And that's just not to put it there in the first place.
NATE: Right. Yes.
CALLI: But reducing emission and carbon capture can work hand-in-hand to get us to net zero by 2050. If this technology can work on a large scale, then we just need to do our part to cut emissions.
NATE: It's a start. And at this point I'm going to take the hope wherever I can get it.
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NATE: It’s common knowledge that you can't have two parents that are the same biological sex. Right. Well, think again, because recent research says that might not be the case.
CALLI: I think you might be confusing common knowledge with just the way reproduction works and semantics.
NATE: But fair enough. What I mean to say is that for the first time ever, scientists have created happy, healthy mice that have two dads and a mom.
CALLI: Okay, that's incredible. I understand almost immediately why people might want this, but I am curious as to why they did it in the first place.
NATE: So this is part of a years long dive into the field of multi parent reproduction. For example, if two men wanted to have a baby together and they could in theory have a child with the help of a surrogate mom that has both their DNA, being that the child would without a doubt be both of theirs biologically something that isn't currently possible with same sex couples.
CALLI: Okay, that's actually really sweet. Like I am absolutely on board for this. So how was the two dad problem solved?
NATE: Trial and error and a whole lot of attempts back in 2020? A developmental biologist named Katsuhiko Hayashi and his team theorized which genes would need to be changed in order for cells placed in a petri dish to turn into a fertile egg. A year later, that same team managed to create a sort of makeshift set of mouse ovaries to foster the eggs and create healthy babies. All that was left was to create eggs out of an adult male mouse's cells.
CALLI: How do you even begin to start a process like that?
NATE: Pluripotent stem cells. We're getting into some complicated reproductive biology here. So hang on tight. Hayashi and his team turned male mouse skin cells that carried X and Y chromosomes into these type of cells. Pluripotent stem cells are able to take on many different forms in the body, allowing for the team to replace that Y chromosome with another X chromosome. After they got these new and improved cells. They doused them in something called reversine, which is a compound that tracks down any cells that had a problematic cell division.
CALLI: And judging by its name, it sounds like they were probably using reversine to reverse this.
NATE: No, actually, what they were looking for specifically were the cells that had two successful X chromosomes or rather fundamentally female cells. And because these were pluripotent stem cells, they were able to manipulate it into becoming egg cells, which they fertilized. And suddenly there you go. They had some brand new embryos. Finally, they put the embryos into a female mouse's uterus.
CALLI: When you tell me a story like this and we already discussed the fact that it worked, I feel like I already know what the results are. But what were the results?
NATE: I feel like when we have stories like this, this is usually the part where I tell you everything was amazing. It was remarkable. But if I'm being honest, these first results weren't that great. Although there is a rather big silver lining. There were 630 custom embryos, 623 of them did not survive. But what's interesting is the seven that did survive, not only were they just fine, but they grew like normal mice into adults and they also became fertile.
CALLI: I'm going to have to disagree with you because this is amazing, because they've never done anything like this before.
NATE: You might be right. And I admit this is a huge step forward for two dad children, but it also means we are years and years away from this becoming any kind of widespread procedure, because no matter how similar mice are to humans, there are still enough differences that a success rate this low doesn't bode well for how this would work with humans under the current methods. So first things first. Hayashi and his team are going to need to analyze each mouse infant to figure out whether or not they're different from a mouse born in a more conventional way. They're also going to need to change the egg growth technique a bit if they try it on humans, which comes with its own whole set of issues.
CALLI: But what kind of issues?
NATE: Humans obviously have larger eggs than mice, so we need a longer time spent on egg growth. And during that time there's a lot of potential for abnormalities to pop up, as one of the biologists on the team puts it. The shorter, the better. There are a number of ways this experiment could set the stage for some pretty big developments, as an example being that it could be the basis for a new treatment for Turner's syndrome, which is a kind of infertility for women who are missing some or all of an X chromosome.
CALLI: But this still sounds really, really hopeful. So we're still hoping that this will work for humans one day, right?
NATE: Most likely it will, yeah. But it's not going to be for a while. And even if it becomes successful, there are all sorts of crazy, ethical and moral questions that this experiment would undoubtedly face, not to mention legal questions, since most laws facing parental guardianship are based around a two parent system. But with all that being said, give it some time because seven of those embryos survived for the first time ever. This might not ever become a widespread solution for humans, but it's definitely a possible one.
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NATE: Let’s recap what we learned today to wrap up. Just when you thought that you were in control of all your life choices, research has found a link between your genes and your fertility - that is, how many babies you’ll have and when you’ll have them.
CALLI: Scientists have found a cheap and effective way to capture carbon in the atmosphere by using methods originally purposed for water filtration. The device needs to be scaled up if it’s going to help us with the ongoing climate crisis but there is hope that eventually this method will be able to help reduce climate change!
NATE: If you’re a same-sex couple that wants to have a child, hope could be on the way. For the first time ever, mice embryos have been created from two male mouse cells and placed into a surrogate mouse mommy, which means that same-sex parenting might soon take on a whole new meaning. Unfortunately, the experiment isn’t successful enough to be applied to humans YET - but it could one day lead to a revolution in bio-engineered parenting the likes of which we’ve never seen before!